1. Field of the Invention
This invention relates to a stretch film wrapping device, and, more particularly, to a device for rotatably supporting a roll of plastic film for tension stretch wrapping of objects, containers and the like.
2. Background of the Invention
In shipping and storing goods, plastic stretch film can be used to both protect and secure a load. The advantages of the use of plastic stretch film are numerous. The stretch film produces a tight wrap and provides protection to the wrapped load from damage due to weather, abrasion, punctures, and the like. The plastic stretch film is of relatively low cost and does not require the use of adhesives, clips or other fasteners. For this reason, the use of plastic stretch film can reduce both material and labor costs.
In order for plastic stretch film to be utilized in an optimum manner, however, the film must be applied to the load at the appropriate tension. If the film is stretched too tight, the film will be difficult to wrap about the load and may break or tear. If the tension in the film is insufficient, the film will not conform to the shape of the load and the film wrap will be undesirably loose. The most important features of a proper wrap are the uniformity and the proper tension of the plastic as it is applied. The proper tension imparted to the film as it is applied results in the desired degree of "stretch" being given the film. The control of the tension must be sensitive and accurate because too much tension will cause the film to undergo plastic deformation and too little tension will prevent a sufficiently tight fit of the film about the package to be wrapped. The sensitivity and accuracy with which the tension must be applied to the film is especially important where the film is of relatively narrow width.
A variety of machines have been developed for applying plastic stretch film. An example of one of these devices is shown in Rimenschneider, III, No. 4,535,951, issued Aug. 20, 1985. The Rimenschneider patent discloses a stretch film wrapping device for two-handed use wherein the roll of film is clamped between two hubs. Two-handed devices or other bulky devices are inappropriate for "orbiting" above the package to be wrapped so as to band or bundle the package with film in both the vertical and horizontal planes.
The devices designed for dispensing plastic stretch film, however, are generally not adapted to permit quick on or off changing of stretch film rolls.